import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: AliceMana
 * Date: 2022-08-14
 * Time: 18:40
 */
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNextLine()) {
            int[] count = new int[250];
            String str = in.nextLine();
            for (int i = 0; i < str.length(); i++) {
                if (count[str.charAt(i)] == 0) {
                    System.out.print(str.charAt(i));
                }
                count[str.charAt(i)]++;
            }
            System.out.println();
        }
    }
}
